Environment Canada predicting warmer winter

El Niño could be good news for Whistler

While no doubt some Canadians are welcoming the Meteorological
Service of Canada’s forecast of a warm, dry winter, the impact on coastal
mountain resorts like Whistler may not be as bad.

According to MSC weather forecaster Peter Jones, the main
culprit behind the warmer temperatures is an El Niño developing over the
eastern Pacific Ocean.

Warmer El Niño waters typically influence temperatures across
Canada, to the extent that it has become one of the more reliable forecasting
tools for meteorologists.

The connection between El Niño and precipitation is less
certain, says Jones, and on the coast it can vary depending on the presence of
an Aleutian low pressure system further north. While most of the country could
experience lower precipitation because of El Niño, the coast could actually be
a great deal wetter.

That, says Jones, is where freezing levels come in and higher
temperatures will have the greatest impact.

“In the end, what we think we know and do know to some extent
is that at lower elevations in the Coast Mountains, 1,200 metres and below,
whatever precipitation falls will fall more as rain proportionally than in a
normal winter,” said Jones. “When you look at Cypress Bowl at 350 metres you
can see the snow at a fraction (of normal) during an El Niño, while at 1,900
metres at the Roundhouse (on Whistler) — where we have records back to
1973 — is more total snow.

“It might be wetter snow on average, because the freezing level
is a little higher, but overall that’s what we’ve seen.”

Some of Whistler-Blackcomb’s best winter seasons, including
1997-98 and 1998-99 were El Niño years.

El Niño conditions in the Pacific so far are rated as weak, but
according to MSC computer models will become moderate by December and the start
of the winter season. As a result there is less likelihood of arctic outbreaks
that last for any length of time, if the southern part of the province sees any
arctic weather at all, and parts of the Lower Mainland will likely stay
snowless throughout the winter.

“Personally I’m a skier so I’m always interested in the data,
and I’m anticipating a lot of questions about this because of the huge economic
impact it could have on the province, a lot of questions about the snow,” Jones
said. “It’s only in rare years that I would take the time to explain what we
know, every other year I would say we’re guessing, don’t waste you’re time on
this even though we put out a seasonal forecast for every season.

“El Niño winters are different — only when El Niño
is moderate or strong do we have any confidence in (the seasonal forecast).”

For December through the end of February, temperatures in the
southern part of the province are expected to be about 1.5 degrees Celsius
warmer on average, with parts of Ontario and Manitoba expecting temperatures
almost three degrees warmer. Temperatures will be close to normal, about one
degree warmer than average, for March, April and May.

In terms of precipitation, the Coast Mountains could see
anywhere from 0.2 to 3.8 additional millimetres per day, averaged out over
December, January and February, while the Interior of the province could see a
drop of 0.3 mm per day on average — depending on the strength and
position of the Aleutian Low.

Precipitation in March, April and May for the Coast Mountains
is forecast to be close to normal, or about 0.1 mm per day above average.

Although there is no established link between El Niño and
global warming, some evidence suggests that there’s an indirect link that
amplifies the effect of the warmer waters on climate.

It’s interesting to note that Environment Canada’s predictions
run against those of the Canadian Almanac, which is predicting temperatures
that are one or two degrees colder on average and near normal precipitation.
The Almanac also predicts that the most snow will fall in mid-to-late November,
from early to mid-January and from mid-to-late February.

While the MSC uses computer models to predict weather, the
Almanac uses a secret formula devised in 1792 and calculations based on solar
activity and sunspots, as well as weather history.